Cluster raisins are also known as raisins on the vine. They are groupings of raisins (formerly grapes) left on the vine to dry with the sun. Some companies cut the grapes and lay them in the sun to dry. Mojave Gold leaves them on the vine to dry naturally and picks them at the peak of perfection. Cluster raisins are generally natural with no chemical processing. The benefit to buying cluster raisins is that you know you have no chemicals, a higher natural sweetness, and plumper raisins.